The State of the Climate Report 2024 has found Australia’s weather and climate has continued to change, with an increase in extreme heat events, longer fire seasons, more intense heavy rainfall, and sea level rise.
The report, prepared every two years, was released by Australia’s national science agency, CSIRO, and the Bureau of Meteorology.
It draws on the latest national and international climate research, monitoring, and projection information to describe changes and long-term trends in Australia’s climate.
Scientists found the oceans around Australia are continuing to warm, with increases in carbon dioxide in the atmosphere leading to more acidic oceans, particularly south of Australia.
CSIRO Research Manager Dr Jaci Brown said warming of the ocean has contributed to longer and more frequent marine heatwaves, with the highest average sea surface temperature on record occurring in 2022.
“Increases in temperature have contributed to significant impacts on marine habitats, species and ecosystem health, such as the most recent mass coral bleaching event on the Great Barrier Reef this year,” Dr Brown said.
“Rising sea levels around Australia are increasing the risk of inundation and damage to coastal infrastructure and communities.
“Global mean sea level is increasing, having risen by around 22 centimetres since 1900. Half of this rise has occurred since 1970.
“The rates of sea level rise vary across the Australian region, with the largest increases in the north and south-east of the Australian continent.”
The amount of greenhouse gases in the atmosphere continues to increase, contributing to climate change, with 2023 the warmest year on record globally.
Dr Karl Braganza, Climate Services Manager at the Bureau of Meteorology, said Australia is continuing to warm, with eight of the nine warmest years on record occurring since 2013.
“This warming has led to an increase in extreme fire weather, and longer fire seasons across large parts of the country,” Dr Braganza said.
The report describes the shift toward drier conditions between April to October across the southwest and southeast, and reduced rainfall in southwest Australia now seems to be a permanent feature of the climate.
“The lower rainfall in the cooler months is leading to lower average streamflow in those regions, which can impact soil moisture and water storage levels and increase the risk of drought. Droughts this century have been significantly hotter than those in the past,” Dr Braganza said.
“However, when heavy rainfall events occur, they are becoming more intense, with an increase of around 10 per cent or more in some regions.
“The largest increases are in the north of the country, with 7 of the 10 wettest wet seasons since 1998 occurring in northern Australia.”
Although Australian emissions have declined since 2005, Australia is projected to see continued warming over the coming decades, with more extremely hot days and fewer extremely cool days.
The rate of emissions decline will need to accelerate from now to meet Australia’s 2030 emissions targets.
State of the Climate 2024 is the eighth report in a series published every two years by CSIRO and the Bureau of Meteorology. The findings highlight the importance of ongoing monitoring and help to inform and manage climate risk.
The 2024 report can be found on the CSIRO and Bureau of Meteorology websites.
-BOM